A recent update to LibreOffice seems to have changed the order in which files and folders are displayed in the File-Open dialogue box. Previously, all the sub-folders were listed ahead of the files in the current folder. Now, files and folders are listed together in alphabetical order. Changing this behaviour is simple, but non-intuitive.
Perhaps it’s me but (a) I couldn’t find a setting in LibreOffice to control the display of files and folders in the File-Open dialogue, and (b) I couldn’t seem to come up with search terms in Google that would provide a solution.
Trial and error experimentation identified one solution. Navigate to File – Open, right-click in the dialogue box to bring up a content menu, and check the box labelled “Sort Folders before Files”.